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Antarctic ice cliffs may not contribute to sea-level rise as much as predicted
- nerdponx 7y agoWhat % of overall sea level rise predictions did this effect contribute? Do we still have to worry about New York and other coastal cities being inundated in the next few decades, or not?
- hannob 7y agoYou still have to worry. This is one study, not a final word on the topic, there's considerable uncertainty in this area. Notably recent numbers indicate that Greenland melting is worse than predicted.
- tropo 7y agoNo, I don't have to worry. That would make me unhappy. Worry is bad for your health. Don't worry about far-off uncertain things that are out of your control. It'd just get you down, paranoid and freaking out, when you could instead focus on the things that matter in life.
- riskable 7y agoIf memory serves some of the more dire predictions accounted for 40 feet of sea level rise as a result of melting ice. This article says that Antarctica's ice shelves (cliffs) would only amount to six feet. So that leaves 'only' 34 feet of sea level rise if the ice cliffs don't collapse as a result of occasional calving and instead gradually melt over time (at a slower pace). Either way it's going to make the sea rise... Just over say, 150 years instead of 50.
- moultano 7y agoSea level rise predictions have the most uncertainty of any climate predictions. We can estimate pretty confidently what the equilibrium level of ice will be from a given temperature from the geologic record, but how quickly we get there depends on a lot we don't fully understand about the physics of ice sheets. One study like this probably shouldn't change your perception of our state of knowledge of this that much, but your baseline should also be that there's huge uncertainty.
- alwaysanagenda 7y agothe hubris of man is that we have enough data to understand the earth at any given moment. https://www.apnews.com/bd45c372caf118ec99964ea547880cd0 https://www.apnews.com/bd45c372caf118ec99964ea547880cd0
- Udik 7y agoExcellent find. Key quote: "The most conservative scientific estimate that the Earth’s temperature will rise 1 to 7 degrees in the next 30 years, said Brown." Dated June 30, 1989 Global temperature anomaly 2018: +0.83 Celsius https://svs.gsfc.nasa.gov/4626 https://svs.gsfc.nasa.gov/4626
- dawg- 7y agoInteresting. It's unfortunate that this will be used as ammunition for climate skeptics. It seems that ice cliffs are very different than ice sheets - the things currently melting. Ice cliffs were previously supposed to account for up to 6 feet of sea level rise, instead of the much more toned-down projections we have seen in the last few years. The subtle distinction between ice cliffs and ice sheets will be lost in the media re-telling of this. Sometimes I wonder if science can ever truly be put to work for mass society? It seems not.
- rimliu 7y agoWhat you say is basically it is too bad that it cannot be used for scaremongering.
- ceejayoz 7y agoNah. It's like having a study come out that shows smoking doesn't cause toenail cancer like the previous ones did. You know the tobacco industry will portray it as "new study shows smoking doesn't cause cancer!" or "scientists cast doubt on smoking-cancer link".
- dawg- 7y agoActually, that's not what I said.
- dawg- 7y agoI also want to mention that I don't agree with whoever flagged the above comment. Silencing and/or hiding people with different opinions is never the way to go.
- jothezero 7y agoMy last post was satirical about the stake, but it is exactly why I mentioned it. I feel like we are in the dark era of Christianity burning witches and dissidents. The More Things Change, The More They Remain The Same.
- pgt 7y agoWhere can I read an unbiased summary of the current state of climate models? Last night I was called "alt-right" and a climate change denier by a peer for hesitating to agree that we are in a climate crisis, because I said don't have enough information about the situation and I'm suspicious whenever too many people start shouting about something. The precautionary principle still prevails, though. The more uncertain you are, the more certain the course of action is, which is to avoid burning hydrocarbons. Edit: I meant to say precautionary principle, not "uncertainty principle".
- serioussecurity 7y agoIpcc report
- elbasti 7y agoThe IPCC report is actually biased--it's too conservative. It doesn't consider positive feedback loops that cause "runaway" change: > By largely ignoring such feedbacks, the IPCC report fails to adequately warn leaders about the cluster of six similar climate tipping points that could be crossed between today’s temperature and an increase to 1.5 degrees—let alone nearly another dozen tipping points between 1.5 and 2 degrees. These wildcards could very likely push the climate system beyond human ability to control. [0]: https://thebulletin.org/2018/10/climate-report-understates-threat/ https://thebulletin.org/2018/10/climate-report-understates-t... (by Nobel prize winner Mario Molina)
- mrpopo 7y agoEvery statement in the IPCC report must be approved unanimously by a panel of authors from various countries. The theories that are not reaching consensus yet cannot be part of it. That's what gives the reports so much weight. Literally everyone should agree with it.
- elbasti 7y agoOf course "weight" does not mean the same as "accuracy".
- ltbarcly3 7y agoFor hundreds of years there have been people predicting some kind of nightmare scenario 'in about 30 years'. In the 1960's and 1970's they were predicting a new ice age, that oil would completely run out, etc etc. More recently they have been predicting extremely rapid climate change, global warming, 'cities underwater', etc. Look at the graph of anticipated sea level rise: https://en.wikipedia.org/wiki/Sea_level_rise https://en.wikipedia.org/wiki/Sea_level_rise Notice anything suspicious? It goes along pretty flat (the historical data looks as linear as it could possibly be), then as soon as you get to right now it jumps up and to the right with exponential growth. If a startup pitched that growth trajectory everyone would know exactly what was going on - high hopes and lies. Except that well meaning idiots have been pitching this for the last 30 years, exponential up and to the right growth of temperature and sea level, and it never materializes. Every few years they just update the graphs to show the small increase that actually occurred and move the exponential explosion so it's always in the near future. Edit: I have noticed people down-voting this comment, that's fine of course, but I wonder whether it's because you think the oceans are going to start rising exponentially - starting right now - or if you think it's dangerous to question climate change dogma because it empowers climate change deniers or something? Or are you just down-voting it because it seems like something you don't like?
- NeedMoreTea 7y agoNotice that from now into the future it is no longer a line, but a range that widens the further into the future it goes. The base of which continues in a perfectly linear fashion. It's attempting to encompass simple progression and the likely impact of tipping points and accelerating melt. So no I don't notice anything suspicious by including uncertainty on the plot. If you look at the range of IPCC predictions, current measured sea level rise is tracking the linear portion of their worst case prediction. (RCP8.5) Draw whatever conclusion you will.
- ltbarcly3 7y agoThis is again a misleading response. If these are uncertainty ranges, it should be statistically absurd for reality to always end up at the extreme low end of the predicted range. How many times does that have to happen before you would have to say the prediction isn't a good one?
- AnIdiotOnTheNet 7y agoITT: A lot of people with no education in climate science proportioning to understand the climate better than the vast majority of climate scientists.
- raarts 7y agoOf course the many people calling themselves climate scientists only know about programming computer models.
- kaybe 7y agoYou'd wish, have you seen the code of scientific models? Coding is one of the things you just pick up on the way, while physics etc is taught formally.
- mistermann 7y ago> the vast majority of climate scientists "97% of climate scientists!!!" right? http://www.storyarts.org/library/aesops/stories/boy.html http://www.storyarts.org/library/aesops/stories/boy.html
- Kaotique 7y agoI will probably get downvoted, but climate change has turned into a religion where any sort of criticism or questions are not appreciated and you are immediately treated as a heretic. Climate change are now a multi-billion dollar industry with a lot of researchers, companies and international and national governments tied up with it. They have zero interest in changing opinion or even questioning if this is all correct. Anyone remember the global cooling scare? Or the nuclear war scare? Or the acid rain scare? People love doomsday thinking. Politicians right and left absolutely love it. Make people scared with all kinds of "end of the world as we know" scenarios and they do whatever you want.
- zorak8me 7y agoThe publication of this article seems to suggest that legitimate criticism and questions are in fact quite welcome.
- ceejayoz 7y ago> Anyone remember the global cooling scare? Largely a myth. https://en.wikipedia.org/wiki/Global_cooling https://en.wikipedia.org/wiki/Global_cooling "Some press reports in the 1970s speculated about continued cooling; these did not accurately reflect the scientific literature of the time, which was generally more concerned with warming from an enhanced greenhouse effect." > Or the nuclear war scare? Still scary. > Or the acid rain scare? Acid rain was mitigated via extensive, global efforts to regulate the pollution emissions that caused it.
- zorak8me 7y ago> Acid rain was mitigated via extensive, global efforts to regulate the pollution emissions that caused it. Excellent point. Big problems are solvable with the right level of effort.
- ceejayoz 7y agoThe arguments you're making - "climate change industry profiting! global cooling! scaremongering!" - tend to be deployed to prevent that effort. It is, for example, rather curious to focus on "multi-billion dollar" climate science but not to count the multi-trillion dollar fossil fuel industry as an interested party.
- dominicr 7y agoA lot of people are going to read only the headline and shout "MIT says global warming isn't true" into their science denial bubbles! From my reading of this, the study does not say that sea-level rise won't happen, it's just saying one theoretical mechanism for RAPID sea-level rise might not be correct, so it'll be slower than some models predict. The study relates to ice cliffs on land and the theory that if the ice shelves in the sea break apart, then the ice cliffs on land will break apart rapidly, contributing to rapid sea-level rise. Ice already in the sea doesn't raise sea-levels but ice currently on land would. The study uses modelling to demonstrate that runaway event is unlikely, so the sea-level rise from that even should be removed from estimates. There's another paper about this from February_:https://www.nature.com/articles/s41586-019-0901-4 https://www.nature.com/articles/s41586-019-0901-4 Some quotes from the papers: - "We’re saying that scenario, based on cliff failure, is probably not going to play out. That’s something of a silver lining. That said, we have to be careful about breathing a sigh of relief. There are plenty of other ways to get rapid sea-level rise." - Ice cliff collapse... "is not required to reproduce sea-level changes due to Antarctic ice loss ... without it we find that the projections agree with previous studies (all 95th percentiles are less than 43 centimetres)." A couple more things: - Both papers still agree that sea-level rise will happen, but maybe not so fast and not so much. (Whether your house is under one foot of water or two doesn't make much difference to if you can live there.) - If your discussion point against climate change is based on the models being wrong/inaccurate/too varied, then you have to discount this evidence, as it too is based on modelling. - MIT's press department need to write better headlines.
- rimliu 7y ago> A lot of people are going to read only the headline and > shout "MIT says global warming isn't true" into their > science denial bubbles! This is an example of the extremely informed and scientific claim.
- tito 7y agoLet's build an interactive display of different models. Like Coinbase.com/charts but for climate models. You can check and uncheck various factors (ice sheets, greenland, methane tundra). Interesting?
- kempbellt 7y agoDoes one already exist? I know there are some for C02 emissions and other useful stats. I am certainly interested in seeing a tool like this.
- tito 7y agoI haven't seen anything useful For example, this looks like it was designed on the Apple II https://www.climateinteractive.org/tools/climate-bathtub-simulation/ https://www.climateinteractive.org/tools/climate-bathtub-sim...
- hanniabu 7y agoThat'd be pretty sweet if you were able to pull it off
- kaybe 7y agoHere is one model that you can download and run: https://www.mi.uni-hamburg.de/en/arbeitsgruppen/theoretische-meteorologie/modelle/plasim.html https://www.mi.uni-hamburg.de/en/arbeitsgruppen/theoretische... It has a GUI mode where you can check and uncheck various things. (Needs a FORTRAN compiler though, and I needed some legacy packages.) edit: It might be less comprehensive that what you mean but it is an actual physical model.
- neom 7y agoArticles like this should discuss how the impact it does have contributes to the whole, climate change is a feedback loop. https://en.wikipedia.org/wiki/Climate_change_feedback https://en.wikipedia.org/wiki/Climate_change_feedback
- yters 7y ago> Scientists have assumed that ice cliffs taller than 90 meters (about the height of the Statue of Liberty) would rapidly collapse under their own weight, contributing to more than 6 feet of sea-level rise by the end of the century — enough to completely flood Boston and other coastal cities. If I understand correctly, these are icebergs. I don't understand how melting icebergs should impact the sea level in the first place. If I melt an ice cube in a cup the water lever remains unchanged. Don't the icebergs already displace as much water as they would contribute? Is there something about icebergs that mean they displace less water, or am I somehow misunderstanding what is going on?
- moultano 7y agoThis is describing cliffs of ice on land, like the Antarctic and Greenland ice sheets. The worry this paper is investigating is whether those could rapidly collapse ones the sea ice that protects it calves off.
- sp332 7y agoAnd in addition to the ice moving from land to water, the land will be less compressed by the weight of ice above it and will rise, displacing even more water.
- yters 7y agoThanks I clearly misunderstood. So it seems the icebergs provided support that the grounded ice did not. How is not exactly clear. Why would icebergs be more supportive than solid ground?
- itcrowd 7y ago> Don't the icebergs already displace as much water as they would contribute? Yes, this is Archimedes' principle. However, large icebergs have a gravitational influence on nearby water. Effectively, large icebergs attract water meaning the local sea level rises and elsewhere on the planet the sea level becomes lower. When the iceberg melts, this gravitational pull disappears and the melt water is spread more evenly across the surface of the Earth. The sea level across the rest of the world thus slightly increases. Modeling this effect is quite complex, but the above is a summary of the effect of melting (large) icebergs.
- cerealbad 7y agoregional hegemons enforce embargoes on nations which refuse to behave according to new standards. a carbon non-proliferation treaty backed with coordinated blockades and cyber-attacks of critical infrastructure, initiating limited civil wars. the top level view is mutual cooperation to avoid global catastrophe. this would require america and russia to stop selling their terrestrial missile technology and fossil fuels to the rest of world. once the current generation of inventory and raw energy is cleared it, orbital space based weapons can be deployed, obsolescing land and sea nuclear delivery and defense. this might explain china and india's rush to space, in order to have a bargaining chip in the future discussion about their territorial and energy sovereignty it is necessary for them to have a significant presence in low earth orbit. things typically don't escalate dramatically during international disputes, and it's likely that the russians and americans will just use blackmail diplomacy to freeze, then develop the rest of the world with new energy they control. in order to avoid public scrutiny it's important to paint this as a critical emergency rather than a strategic sharing of influence between continental superpowers. i suspect this will play out slowly over the next century, all the while regular people will be cowed by the ever looming threat of total extinction. not a very original sequel, a real throwback your parents might enjoy, cold war 2: fight the heat. the science on anything hardly matters, since scientific truth is subservient to pragmatism and political realities. given the massive investment in government information collection, it is clear that any large popular movement would quickly be steered towards desired policy goals, which should reinforce some version of the above story i laid out.
- tito 7y agoHere's the academic paper the article references: https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2019GL084183 https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2019... Not showing up on Scihub tho. Anyone found it?
- hackeraccount 7y agoI get suspicous when people start shouting and screaming that the only way to do anything about climate change is X - where X might or might not reduce greenhouse gases but definately aligns with there politial prirors. I also don't like the fact that these same people seem to have no respect at all for economic growth. I firmly believe that any realy solution will be an encouragement to growth not a discouragement.
- tito 7y agoThe changing climate will create the first trillionare.
- JoeAltmaier 7y agoEconomic growth? How does the imaginary game of wealth-points intersect with preserving the planet's ecosystem? I can imagine many scenarios for saving the planet, that are detrimental to human interests. Nuke all major population centers, for instance. Ban burning oil entirely. Begin sequestering all crops in the bottom of the ocean as CO2 sinks. To confuse human trivia with planetary disaster is one of the first refuges of naive deniers - "Well, we sure can't go without our cars, don't be ridiculous!"
- kaybe 7y agoReducing and eventually eliminating net emissions is not optional. How we get there can be discussed - if you have any better ideas please put them forward!
- hlesesne 7y agoI may be completely missing something, but I was under the impression that floating ice has zero impact on sea levels - a unique characteristic of water. Ice floating in water in a cup already at the top won’t overflow when it melts. It seems like only land-supported ice sheets would have any impact at all anyway. Where were they getting the 6 foot rise in the first place? The violent water displacement when the cliff falls?
- moultano 7y agoThe article is about land ice.